Preparation of organocalcium compounds

ABSTRACT

POLYMERIZATION INITIATORS ARE PRODUCED FROM SUBSTANTIALLY PURE CALCIUM METAL TOGETHER WITH POLYNUCLEAR AROMATIC COMPOUNDS OR POLYARYL SUBSTITUTED ETHYLENE.

3,642,922 Patented Feb. 15, 1972 018 ORGANOCALCIUM COMPOUNDS CarlAI'Ur'aneck, William J. Trepka, and James D. Brown, Bartlesville, kla.,assignors to Phillips Petroleum Com- P y No Drawing. Filed Dec. 16,1968, Ser. No. 784,177 Int. Cl. C071 3/04; C08d 3/06 US. Cl. 260-665 RPREPARATION 7 Claims ABSTRACT on THE DISCLOSURE P'Polymerizationinitiators are produced from substantially pure calcium metal togetherwith polynuclear aromatic compounds-or 'polyaryl substituted ethylenes.

tiators are effective for the polymerization of hydrocarbon monomers toform homopolymers and copolymers of random and block configurations, butthey are often not suitable for the polymerization of various othertypes of monomers such as u,/8-unsaturated nitriles, esters of acrylicand methacrylic acid, vinylpyridines, vinylquinolines,

vinylpyrrolidones, vinyl ketones, vinyl esters, and the like. Theseorganoalkali metal compounds often react with these latter namedmonomers at temperatures ordinarily suited for polymerization instead ofefiecting polymer formation.

When producing an organocalcium compound, it has been thought necessaryto first activate the calcium by contacting it with mercury to form analloy or amalgam before contacting it with an organic component, or byforming a combination with organocalcium halides and other materials inorder to produce organocalcium compounds that are complexed.

It has now been discovered that polymerization initiators can'beproduced from polynuclear aromatic hydrocarbons and frompolyaryl-substituted ethylenes when contacted with elemental calciumwithout first forming the alloy or amalgam with mercury.

Ityhas also been discovered that the unique calcium initiators that areformed according to this invention are effective polymerizationinitiators capable of polymerizing a large variety of monomerscomprising unsaturated organic compounds which generally contain thecharacteristic structure CHFC These initiators can, like theorganoalkali metal initiators, initiate the polymerization of conjugateddienes and vinyl substituted aromatic hydrocarbons.

'Our novel initiators are efiective, not only to polymerize monomers ofthe styrene and butadiene type, but are capable also of initiating thepolymerization of monomers States Patent Cffice such as polymerizable, ce-unsaturated nitriles, esters of acrylic and methacrylic acid, vinylketones, vinylpyridines, vinylquinolines, vinylpyrrolidones, and vinylesters and the like at temperatures ordinarily suited forpolymerization.

It is an object of this invention to produce a novel polymerizationinitiator capable of initiating polymerization of broad varieties ofpolymerizable monomers such as conjugated dienes, vinyl substitutedaromatic hydrocarbons, a,fi-unsaturated nitriles, vinyl ketones,vinylpyridines, vinylquinolines, vinylpyrrolidones, esters of acrylicand methacrylic acid, or vinyl esters, and the like.

It is another object of this invention to provide an improved method forproducing calcium polymerization initiators by eliminating the amalgammercury activation process and thus eliminate the handling of this toxicmaterial as well as jointly conserving time and expense.

It is still another object of this invention to provide a novelpolymerization process incorporating the polymerization initiators ofthis invention. Other objects, advantages, and features of our inventionwill be apparent to those skilled in the art from the disclosure anddiscussion herein set forth.

The polynuclear aromatic/calcium compounds produced according to thisinvention are prepared from aromatic hydrocarbons containing at least aS-ring structure in which at least two of said rings are aromatic and atleast two of said rings are fused and said polynuclear aromatichydrocarbon comprises from 12 to 40 carbon atoms per molecule. Thesepolynuclear aromatic hydrocarbons can contain alkyl, cycloalkyl, aryl,alkoxy, aryloxy, alkylthio, arylthio, or N,N-dialkylamino substituentsand combinations thereof such as cycloalkyl, arylalkyl, and the like,wherein the carbon atoms of the substituents total not more than 25.Exemplary of those polynuclear aromatic compounds which can be utilizedaccording to this invention comprise anthracene;9,10-dimethy1anthracene; 9,10-diphenylanthracene; phenanthrene;9,10-benzophenanthrene; 2,3 benzanthracene; 1,2 benzanthracene;chrysene; acenaphthylene; perylene; fiuoranthene; 3 (3-ethylcyclohexyl)anthracene; 4 (2-cyclohexylethyl)-tetracene; 4,7diethoxyfiuoranthene; 1-phenoxy-6-methylcoronene; 6(ethylthio)aceanthrylene; 6,8 di(phenylthi0) hexacene; 7(N,N-diethylamino)acephenanthrylene; 3, 8,14 (triphenoxy)trinaphthylene;1,3,6,8 (tetraphenylthio)pyrene; 1,15-(dipentyl)pyranthrene;4-(N,N-dimethylamino)perylene; heptaphene; heptacene; pentaphene;rubicene; pleiadene; pentacene; l,4,8,1l-(tetracyclohexyl) pentacene; 9methylanthracene; 9-phenylanthracene; 9, 10 dicyclohexylanthracene; or9,10 di(N,N-dimethylamino)anthracene; and the like.

The polyaryl-substituted ethylene calcium compounds produced accordingto this invention are prepared from ethylene that has been substitutedwith at least two aryl radicals and said polyaryl-substituted ethylenecompound contains from 14 to 40 carbon atoms per molecule. These saidaryl substituents can contain alkyl, cycloa1kyl,aryl, alkoxy, aryloxy,alkylthio, arylthio, or N,N-dialkylamino radicals and combinationsthereof such as cycloalkylalkyl, arylalkyl, and the like, wherein thetotal carbon atoms of these latter radicals total not more than 25.Exemplary of those compounds which can be utilized according to thisinvention comprise cis and trans 1,2-diphenylethylene(stilbene);

1,1-diphenylethylene;

triphenylethylene;

tetraphenylethylene;

1-phenyl-2-( l-naphthyl ethylene;

l, l-diphenyl-Z- 2-naphthyl) ethylene;

l,2-di( l-naphthyl) ethylene;

l-(4-methoxyphenyl)-1-(4-phenoxyphenyl) -2- [4-(3-methylcyclopentyl)phenyl]-2-(4-cyclohexylmethy1- phenylethylene;

l-(4-methylthiophenyl) -1-(4-phenylthiophenyl) -2- [4-(N,N-dimethylamino phenyl] ethylene; tetra- (4-phenoxyphenyl) ethylene;tetra-( l-naphthyl) ethylene, and the like.

When preparing the initiators of this invention, substantially pureelemental calcium is employed in the form of turning or shot, or thelike, so as to provide a form of calcium with as much exposed surfacearea as possible. It is important that the calcium be protected from airand maintained accordingly so as to prevent the formation of oxidesthereon.

The polymerization initiators of this invention comprise the reactionproducts which form when the polynuclear aromatic compound or thepolyaryl-substituted ethylene and the elemental calicum are broughttogether at a temperature in the range of about 100 to 200 F.,preferably about to 125 F. The contacting is carried out in the presenceof an ethereal diluent of monoor polyethers including acyclic and cyclicethers. Alkyl, aryl or cycloalkyl ethers, or combinations thereof,containing 2 to 20 carbon atoms per molecule and about 1 to 4 ethergroups per molecule can be employed. Exemplary ethers are diethyl ether,dibutyl ether, methyl butyl ether, phenyl methyl ether, diphenyl ether,cyclohexylmethyl ether, tetrahydrofuran, 1,2-dimethoxyethane,1,4-dioxane, and the like. Tetrahydrofuran; 1,2-dimethoxyethane; and1,4- dioxane are the preferred diluent ethers.

The ethereal diluents are believed likely to form ether complexes withthe organocalcium initiator thus formed.

When a very finely divided calcium form is employed such as produced bythe vaporization of calcium in an electric furnace as described V. Sinn,B. Francois, N. Mayer, and J. Parrod in Compt. Rend. (Paris), 262, Ser.C, pp. 541-544 (1966), it is unnecessary to contact the organic compoundwith the calcium in the presence of an ether diluent. The contacting canthen be carried out generally in any inert diluent such as aliphatic,aromatic, cycloaliphatic, or araliphatic hydrocarbon and the like, andthe ether need not then be employed.

Employment of the vaporized metal is not the preferred procedure due tothe more costly and complex electric furnace procedure used for thepreparation of such a very finely divided metal.

Metals that have been prepared by such a method often possesspolymerization initiator activity themselves, but are, however,generally inferior to the initiators of this invention. The solutions orsuspensions of the initiators produced according to this invention aremore easily handled in charging, measuring, or other transfer operationsthan the vaporized metal themselves. This subsequently results inimproved control of the polymerization reaction in terms of initiatorlevel and thus the molecular weight of the polymer.

Another disadvantage of conducting polymerization reactions with finelydivided metals, as produced by the electric furnace method, is that theyoften show long in duction periods and then rapid uncontrolledreactions.

Also, these very finely divided metals are more susceptible toinactivation by accidental contact with air or other oxygen-containinggases resulting in inactivation of large portions of the finely dividedmetal by the formation of an oxide surface coating thereof.

The ratio of gram atoms of calcium to moles of polynuclear aromaticcompound or to moles of polyaryl- 4 substituted ethylene is in the rangeof about 1:1 to 25:1. It is preferred to use an amount of calcium inexcess of the 1:1 ratio with the more preferred ratio being from 4:1 to15:1.

Aquantitative determination of the extent of product formation can bemade by employing a hydrolyzed portion of the organocalcium reactionmixture and analyzing by titaration, with an acid such as hydrochloricacid and employing phenolphthalein as an indicator or by any othersuitable analytical method known to the art, so as to measure thealkaline molarity of the reaction mixture. When the alkaline molarity ofthe calcium adduct reaction mixture is essentially equal to the molarconcentration of the starting polynuclear aromatic orpolyaryl-substituted ethylene compound essentially complete conversionto the calcium adduct has been obtained assuming that only one gram atomof calcium forms an adduct with one mole of polynuclear compound.

Qualitative evidence of the initiator formation occurring is readilyapparent from the usually vivid color transformation that occurs whenthe initiator begins to form. The color and degree and rate of colorchange will depend, in part, upon the particular organic compoundemployed.

Organic promoters which react immediately to expose fresh calciumsurface metal can also be employed during the preperation of theinitiator. Alkyl or alkylene halogencontaining promoters such as1,2-dibromoethane, methyl iodide, ethyl bromide, or ethyl iodide and thelike function accordingly. The well-known Grignard reaction utilizessuch promoters and is described in Organo-Metallic Compounds by G. E.Coates, pages 46-47, 2nd edition, John Wiley & Sons, Inc., New York(1960).

The amount of promoter, if employed, is generally in the range of about0.002 to 0.2 mole, preferably about 0.005 to 0.1 mole per gram atom ofcalcium, and preferably containing the bromide or iodide halogen andwith 1,2-dibromoethane being the preferred promoter for use with thisinvention.

The initiators, if washed in a non-reactive liquid in which they areless soluble (in comparison to ethereal diluent in which they wereoriginally formed), show improved initiator activity.

The washing removes excess unreacted organic components and removesexcess diluent ether.

Aliphatic or aromatic hydrocarbons such as xylene, toluene, n-pentane,or iso-octane are suitable washing liquids. Toluene is the washingliquid preferred. The initiators suitable for washing, as hereindescribed, are those recoverable from the ether diluent. The calciumanthracene compound is particularly suited for washing for it issufficiently insoluble in the ether diluent in that it precipitated asit was formed.

As hereinbefore mentioned, the calcium initiator of this invention canbe used to polymerize a broad variety of monomers to form homopolymersor random and block copolymers.

Conjugated dienes, vinyl-substituted aromatic hydrocarbons,a,fl-unsaturated nitriles, esters of acrylic and methacrylic acid, vinylketones, vinylpyridines, vinylquinolines, vinylpyrrolidones, vinylesters and the like are etfectively polymerized in the presence orabsence of diluents. Any diluent which is relatively inert,non-deleterious, and liquid under the reaction conditions of the processcan be utilized. Hydrocarbon diluents such as parafiins, cycloparaifins,aromatics and the like, can be used as well as others well known to theart. Conditions ordinarily suited and well known in the art forpolymerization can be employed with temperatures generally in the rangeof about -l00 to 200 F., with the range from 20 to 125 F. beingpreferred. Higher and lower temperatures can be employed if desired. Theinitiator is generally employed in a concentration of about 0.1 to grammillimoles per 100 grams of monomcrts) employed (mhnr) and preferablyabout 1 to 20 (mhm.). Exemplary of these polymerizable compounds areacrylonitrile; methacrylonitrile; cinnamonitrile; 2- butenenitrile;2-octenenitrile; 2- dodecenenitrile; 2-methyl-2-decenenitrile; methylacrylate; ethylacrylate; butyl acrylate; cyclohexyl acrylate; octylacrylate; dodecyl acrylate; methyl methacrylate; ethyl methacrylate;butyl methacrylate; cyclohexyl methacrylate; octyl methacrylate;-dodecyl methacrylate; benzyl acrylate; benzyl methacrylate; vinylacetate; vinyl butyrate; vinyl Z-ethylhexanoate; vinyl octanoate; vinylcyclohexanoate; .vinyl benzoate; vinyl phenylacetate; vinyl dodecanoate;methyl vinyl ketone; benzyl vinyl ketone; ethyl vinyl ketone; butylvinyl ketone; octyl vinyl ketone, phenyl vinyl ketone; l-naphthyl vinylketone; Z-ethylhexyl vinyl ketone; cyclohexyl vinyl ketone; cyclododecylvinyl ketone; 3 methylcyclopentyl vinyl ketone; 4-ethylphenyl vinylketone; decyl vinyl ketone; S-cyclopentyl-Z-naphthylvinyl .ketone;styrene; 4-ethylstyrene; l-vinylnaphthalene, 2-vinylnaphthalene;9-vinylanthracene; 3-vinylphenanthrene; 4-dodecyls tyrene;alpha-methylstyrene; 2-alphamethylyinylnaph'thalene; 1,3-butadiene;isoprene; 2,3-dimethyl-1,3-butadiene; 1,3-pentadiene; 1,3-hexadiene;4,5- diethyl-1,3-octadiene; 2 -'phenyl'-l,3-butadiene; 3-methyl-l,3'-heptadiene; 2 viny1pyridine; 4-vinylpyridine; Z-methyl-S-vinyIpyridine; 4-vinylquinoline;2-methyl-8-vinylquinoline;1-vinyl-2-pyrrolidone; or1-viny1-3,3-dimethy1-2-pyrrolidone; and the like,

The reaction medium employed for preparing the calciuni initiators isalso suitable for the polymerization process. An ll'l Sl'fLl techniquecan be employed for preparing the initiators and for conducting thepolymerization process. In" this method of operation, all materials forinitiator preparation and polymerization are charged initially. As thecalcium reaction'pr'oduct is formed it initiatesypolymerization of themonomer present in the system.

, Since many types of monomers can be polymerized in the presence ofthis initiator, a Wide variety of products can'be obtained. Productsranging from low to high molecular weight are produced depending uponthe monomers used aswell as the type and amount of initiator. Productscan be obtained which range from liquids to elastomers and'hardplastics.

'Thesolid polymers prepared according to our invention can be employedto produce by conventional methods various molded plastic articles suchas containers and the like'. The polymers can also beblended with eachother, or'vy ith. various types of known polymeric products to produceuseful articles. The low molecular weight polymers of .conjugateddienescanjbe vulcanized to produce hard, resinous pot'ting compoundsfor theelectrical industry. They can also be employed for various other usessuch as plasticizers, tacki-fiers and the like. The elastomericpolymers'ca'nibe compoundedwith vulcanizing agents. fillers,antioxidants, plasticizers, extender oils and the like to producerubbery products suitable for use as tire trends, hose, belting, gasketsand the like.

EXAMPLE I Anthmcend Acenaphthylcne I; i I

6 Perylene Q9 Fluoranthene 1,2-B enzanthracene 2,3-Benzanthracene9,10-D1phenylanthracene {V011 CaHa 9,10-D1methylanthracene CH2Pheuanthrone G Ohrysene m Stllbone H l1 Tetraphenylethylelie The calciumwas employed in the form of turnings or shot. The recipe was as follows:

Polynuclear aromatic compound,

mole Variable. Calcium, gram atoms 0.10 1,2-dibromoethane, mole 0.001(0.10 ml.). Tetrahydrofuran, ml 100. Temperature, F. Variable. Time,hours Variable.

Except for run where 0.016 gram atoms was used.

Table I summarizes the data for the experiments including the quantitiesof the various materials employed for the preparation of theorganocalcium initiator adducts, the ratio of gram atoms of calcium tomoles of polynuclear aromatic compound, temperature, time of eachreaction, alkalinity, and conversion of polynuclear hydrocarbon.

In Runs 1, 2, and 6, the polynuclear aromatic compound was charged firstfollowed by the calcium and then the tetrahydrofuran. The reactor wasflushed with argon and 1,2-dibromoethane was added. In Runs 3 and 7through 16, the polynuclear aromatic compound, calcium, tetrahydrofuran,and 1,2-dibromoethane were charged in the order listed. The reactor wasnot flushed with argon. In Runs 4 and 5, tetrahydrofuran was chargedfirst after the reactor was purged with nitrogen. Calcium was added andthen the polynuclear aromatic compound. The reactor was flushed withargon and after 4.5 hours the 1,2- dibromoethane was introduced.

The alkalinity of each reaction product was determined by titration of ahydrolyzed portion of the reaction mixture with 0.1 N HCl and the extentof conversion of the polynuclear aromatic compound as beforementioned tothe organocalcium initiator was calculated from the titration value.

the temperature was adjusted to the level employed for thepolymerization, and the initiator was added.

In Runs 1 through 4, and 25 and 27, for the homepolymerization ofbutadiene, a 10 weight percent solution of2,2-methylene-bis(4-methyl-6-tert-butylphenol) in isopropyl alcohol wasadded at the completion of the polymerization time, the amount usedbeing sufiicient to provide approximately 1 part by weight ofantioxidant per 100 parts by Weight of the polybutadiene. In all of theother polymerization runs, isopropyl alcohol was added alone. Polymerswere recovered by coagulation in isopropyl alcohol. They were driedunder a vacuum at 140 F.

Runs 14 through 16 represent the production of copolymers from methylmethacrylate and a second monomer. Toluene was charged first after whichthe reactor was purged with nitrogen. The monomer other than methylmethacrylate was added, i.e., butadiene, styrene, or ethyl vinyl ether,then the methyl methacrylate, the temperature was adjusted to the levelemployed for polymerization, and the initiator was introduced last.

In Runs 17 through 20, which represent the production of blockcopolymers, cyclohexane was charged first, the reactor was purged withnitrogen, methyl methacrylate was added and the temperature was adjustedto 41 F. The initiator was then introduced. After 18 hours the secondmonomer was added. The temperature was maintained at 41 F. for 66 hours,and then increased to 122 F. and maintained at this level for 18 hours.Runs 23 and 24 also represent the production of block copolymers.Toluene was charged first, the reactor was purged with nitrogen, methylmethacrylate was added, the temperature was adjusted to -22 F., and theinitiator was introduced. Run 9 also represents the production of ablock copolymer of styrene/butadiene and the polystyrene segment wasanalyzed at 8 weight percent of the total polymer.

TABLE I Cazpoly- Conv. of

Polynuclear hydrocarbon nuclear Alkahydrocar- Hc, mole Temp., Time,llnity, bon, wt.

Run N 0 Type Moles ratio F. hrs. N percent 1 Anthracene 0.025 4:1 122 980. 210 42 2. Acenaphthylcnc. 0. 010 10:1 122 144 0. 102 51 3- .-do..- 0.025 4:1 122 74 0. 28 55 4. ..do--. 0. 025 4:1 22 74 0. 25 50 5- ..do-0.025 4:1 41 75 0. 286 67 6. Perylene 0. 010 10:1 122 195 0. 119 59 7...Fluoranthene 0. 010 10:1 122 74 0. 080 8.. 1,2-benzanthracene... 0. 01010:1 122 195 0. 053 26 9-.- 2,3-benzanthracene 0. 004 4:1 122 144 0.02025 10 9,10-diphenylanthracene. 0.010 10:1 122 195 0. 038 19 119,10-din1ethylanthracenc 0. 010 10:1 122 100 O. 045 12 Phenanthrene 0.025 4:1 122 144 0. 027 6 13-. Chrysene 0. 025 4:1 122 144 0. 027 6 14..Stilbene 0. 025 4:1 122 73 0. 027 6 15 Tctraphcnylcthyleno 0. 007 14:1122 144 0. 014 10 Example I exemplifies fruition of this invention bysuccessfully demonstrating the preparation and production of theorganocalcium initiators of this invention.

EXAMPLE II The organocalcium initiators of Example I were employed asinitiators for homopolymerization, and for random and blockcopolymerization, employing a series of exemplary monomers. Table IIsummarizes the quant ties of the various monomers employed, thequantities of the particular initiator from Example I, the temperature-In Run 23, Z-methyl-S-vinyl-pyridine was added after 0.75 hour and thereaction was continued at 22 F. for 14.9 hours. In Run 24,N-vinyl-Z-pyrrolidone was added after 0.5 hour and the reaction wascontinued at 22 F. for 15.5 hours.

Microstructures for the polybutadiene in Runs 1 and 25 were as follows:

Run 1 Run 25 Cis, percent 7 14 Trans, percent 75 66 Vinyl, percent 18.20

thus showing that the polymer was predominantly the 1,4-addition productand that the major portion of the uusaturation thereof contains thetrans configuration.

TABLE II Monomers Diluent Initiator Run Parts I Parts From Temp Time,Conv., Inherent No. 'I'ype by wt. Type bywt. run Mmoles hrs. percentviscosity Type of product 1 1,3-butadiene 100 oyclohexaneu 780 1 5.0 12224 100 0.6 Soft rubber. 2 do 100 do. 780 1 2.7 122 16 100 1.78 Rubbersolid. 3 100 -do 780 1 3.4 122 23 88 1.44' Do. 4 100 --do--- .780 1 2.26122 20 88 1.75 Do. 5 100 0..-. 780 1 5.0 122 24 32 0. 04 Solid polymer.100 To1uene--.- '870 1 4.8 41 27 100 3. 76 Toulgildi, flexible so 100Cyclohexane 780 1 5.9 158 22 98 .46 Soft rubber. 100 Toluene 870 1 40 692 2 24 Powder.

5? }Cyclohexane 780 1 2.7 122 27 97 1.63 g$g 10. Methyl'vinyl ketone 100.-do 780 6 5. 0 41 47 80 1 0. 05 Sticky solid. 1l Methyl methacrylate100 Toluene 870 3 5.0 :1 27 100 3.03 Had,tbrittle l p as ic. 12.2-metl1dy1-5-vinyl 100 do 870 3 122 3 28 3 Viscous liquid.

pyr me. ficrfiyllolnitritlfifl lgg 870 4 6.0 41 24 44 1.15 gowdrenfl b]eymea oug,ex1e 14 1,3-butadiene 60 870 5 41 21 63 solid. 15 870 5 5.0 4121 60 Methyl methacry 50 D0. "i n n i l iny l 2 5 21 l i B m d e y meacrya 6-... l8+66 0 r eso 17 "{l,3-butadiene 50 5 M {122 18 1 plastic.1B --{t5y .%..3ii.3??f. 'if?:::: 28 780 5 {ft 18+ 22 l 43 Brittle Solid-Methyl methacrylate 50 41 18+66 19 2-rnfdthl-fi-vinyl 50 5 {122 18 i DY20 {Methylmethacrylate 780 5 o 41 18+66 549 Do Methacry1onitrile 50 12218 21.- Methyl vinyl ketone 100 780 6 5.0 41 47 70 '0.06 Do. 22 Ethylacrylate 100 870 6 10.0 41 53 16 Soft, tacky elastomei. ethylmethacrylate 50 870 6 -22 0 75-1-14 9 56 Tough, flexible 232-methyl-5-vinyl 50 slid.

pyridine. 24 {Methyl methacrylate- 50 d 870 6 10.0 22 0. 5+15. 1 60Brittle solid.

N-vinyl-2-pyrrolidone... 50 0 25.. 1,3-butadiene 100 Gyolohexane 780 74.0 122 24 76 0.42 Very soft rubber 20 Methyl methacrylate .100 Toluene870 7 3.0 41 24 69 4.17 Brittle solid. 27.. 1,3-butadiene 100Cyclohexane 780 8 2.0 122 24 15' Liquid. 28. Styrene 100 Toluene s70 116.8 122 69 29 Methyl methacrylate 100 do 870 11 4.5 41 69 l Determinedin chloroform.

2 Determined in dimethylformamide.

8 Temperature 41F. for 28 hours, then 122F. for 18 hours. 4 Productcontained 0.79 weight percent nitrogen.

v Product contained 5.1 weight percent nitrogen.

The above example and the data in Table H demonstrate that a variety ofproducts including liquids, clastomers, and plastics can be producedfrom a variety of types of monomers using the organocalcium initiatorsof this invention, and that very high'molecular weight polymers areproduced by the homopolymcrization of methylmethacrylate.

EXAMPLE HI As in situ technique was employed in which an initiator was.formed in the presence of monomer and the polymerization of the monomerthen occurred. The following recipe was employed.

Styrene, grams 10 Tctrahydrofuran, ml. 100 iAnthracene, mole 0.025Calcium, gram atom 0.05 1,2-dibromoethane, ml --1 0.1 Time, hours 48Temperature, F. 122 Conversion, percent .100

alcohol and was separated and dried. The inherent viscosity of thepolymer was 0.19. The above example demonstrates that the in situtechnique can be employed wherein the organocalcium initiator adduct isformed in the presence of the monomer which is then polymerized.

EXAMPLE IV The calcium/anthracene initiator, as employed in Run 1 ofTable I was used to demonstrate the effect of washing the initiators ashereinbefore mentioned.

After the reaction and formation of the calcium/anthracene initiatorcompound had been accomplished, the reaction product was separated fromthe tetrahydrofuran; the tetrahydrofuran being withdrawn followingcentrifugation. This initiator was washed (stirred) with ml. of tolueneat 122 F., for 30 minutes. The mixture was centrif uged, toluenewithdrawn, and the washing was repeated. This washed initiator and theunwashed initiator of Runl, Table I, were employed for thepolymerization of butadiene. The recipe was as follows:

1,3-butadiene, parts by weight 100 Cyclohexane, parts by weight 780Initiator, mhm. variable Temperature, F- c 122 Time, hours 20 Mhm.=grammillimoles per 100 gram monomer.

The results are reported in Table III.

. TABLE I11 Initiator (washed) Initiator (unwashed) Initiator. mhm 2.343. 51 4. 68 2, 26 3. 48 4. 70 Conversion. percent 100 98 96 88 88 94Inherent viscosity 2. 56 1.66 1. 33 1. 75 1. 32 0.98

Mierostrueture. percent:

Cis 14. 9 12.0 13. 1 12.1 12. 4 15. 2 Trans 77.1 79. 6 78. 4 76.1 76. 371. 4 Vinyl 8. 8.4 8. 11. 8 12. 3 13. 4

These data show that by washing the initiators of our invention with anon-reactive liquid in which the initiator is less soluble, i.e., whencompared to the solubility of the initiator in the ethereal diluent inwhich it was prepared, that increased monomer conversion and polymerswith a higher inherent viscosity at a given level of initiator areproduced.

Evaluation of some polymers initiated with the organocalcium initiatorsof this invention are represented in Table IV.

Polymers A, B, and C represented therein are those polymers previouslyproduced and represented in Table II, Runs 3, 2, and 9, respectively.

For comparative evaluation purposes, polymers initiated by initiatorsother than those of this invention were likewise evaluated. The datareported in Table IV demonstrate that the polymers prepared with theorganocalcium initiators of this invention exhibit, not only excellentproperties in general, but display much higher tear strength than thepolymers produced by other initiators. The data also demonstrate theprocessibility of the polymers of this invention.

Comparative control polymers D, E, F, and G, respectively, are a43-Mooney emulsion polybutadiene; a 45- Mooney polybutadiene preparedwith an organoaluminum and a titanium halide initiator; a 37-Mooneysolution polybutadiene prepared with an organolithium initiator; and a49-Mooney, 75/25 butadiene/ styrene copolymer prepared with anorganolithium initiator.

As will be evident to thoseskilled in the art, various modifications ofthe invention can be made, or followed in light of the teachings anddiscussion set forth herein without departing from the scope or spiritof our invention.

We claim:

1. A process for producing organocalcium polymerization initiators whichcomprises contacting substantially pure calcium metal with a polynucleararomatic compound or polyaryl-substituted ethylene, in the presence of adiluent consisting essentially of an ether containing 2 to 20 carbonatoms and 1 to 4 ether groups, and in the further presence of apromoter, and said promoter is a halogen-containing organic compoundthat reacts substantially immediately to expose fresh calcium surfacemetal, wherein said contacting is at a temperature in the range of fromabout 100 to 200 F., the ratio of gram atoms of said calcium metal tomoles of said polynuclear aromatic compound or said polyaryl-substitutedethylene is in the range of about 1:1 to 25:1; and said promoter isemployed in the range of about 0.002 to 0.2 mole per gram atom of saidcalcium metal; wherein said polynuclear aromatic compound comprises anaromatic hydrocarbon containing at least a 3-ring structure in which atleast two of said rings are aromatic and at least two of said rings arefused and wherein the total number of carbon atoms per molecule is from12 to 40; said polyaryl-substituted ethylene contains at least twoaryl-substituted radicals and has from 14 to 40 carbon atoms permolecule; and said polynuclear aromatic compound or thepolyaryl-substitutes of said polyaryl-substituted ethylene can containalkyl, cycloalkyl, aryl, alkoxy, aryloxy, alkylthio, arylthio, orN,N-dialkylamino radicals and combinations thereof, wherein the totalcarbon atoms of these latter radicals total not more than 25.

2. The process of claim 1 wherein said polynuclear aromatic compound orsaid polyaryl-substituted ethylene TABLE IV.-EVALUATION OF CALCIUMADDUOT INITIATED POLYMERS olymer Characteristic] Polystyrene, percentPolymer wt IRB #2. Zinc oxide. Stearic acid. Flexamino Philricli 5Sulfur NOBS Special 1.1 1.1 1.1 1.2 1.0 1 1 1.0

Processing data (6 x 12 inch roll mill) Compd ML-4 at 212 F 30 52 61 7450 52 Rheometer at 307 F.

Max. viscosity, units 35. 4 46. 5 38.6 60. 3 69. 2 76. 0 57. 1 Curerate, units/min 6. 00 6. 8 4.1 4. 5 6.8 10. 8 6. 3 cure, min 18.2 10. 522. 2 34. 8 23. 7 24. 0 28. 8 Reversion, min 35. 8 30.1 45. 5 None 52. 449. 0 53. 5

Physical properties (30 min. cure at 307 F.)

Compression set, percent 11 28.1 21.3 21. 7 20.1 16. 5 19. 2 20. 4 300%modulus, p.s.i. 580 590 1,180 1,075 865 970 1, 210 Tensile, p.s.i.: 1,965 2, 650 3, 300 2, 600 2, 360 2, 315 3, 565 Elongation, percent 650700 640 540 550 500 610 AT, F3 130.8 88.0 96.4 74.4 60.3 71.0 64.4Resilience, percent L. 55. 4 61.1 54. 6 58. 7 69. 3 68. 4 65. 2 Shore Ahardness 54. 5 56. 6 69 56 58 60. 5 59 Tear, 80 F., lb./in. 280 295 330225 225 Calcium-anthracene reaction product. ASTM D 1646463. Determinedaccording to Kolthoil, et al, I. Polymer Sci. 1, 420 (19-16).

4 A physical mixture containing 65% of a complex diarylamine-kctonereaction product i 3; The process of claim l wherein said ether diluentis tetra'l iydrofuran, 1,2-dimethoxyethane, or 1,4-dioxane.

4. The process of claim 1 wherein said promoter is 1,2- dibromoethane,'methyliodide, ethyl bromide, or ethyl iodide.

5. The process of claim 1 wherein said organocalcium polymerization,initiator is recovered and washed in a non-reactiveliquid wherein saidnon-reactive liquid comprisesa liquid in which said organocalciuminitiator is less soluble than in said ether diluent.

. I 6 The process of claim 5 wherein said liquid is toluene. 7. Theprocess of claim 1 wherein the substantially pure calcium metal has beenfinely divided by the vaporization thereof.

References Cited UNITED STATES PATENTS- 3,509,067 4/1970 Bostick 252-431 2,800,559 7/ 1957 Ubbelohde 20163 3,354,190 11/ 1967 Ramsden2-60429.7 3,479,320 11/ 1969 BOStiCk 260-465 OTHER REFERENCESBryce-Smith et al., J. Chem. Soc. (0) 1966 pp. 154-7. Meals J. Org.Chem. vol. 9 (1944) p. 211, 213. Gilman et al., J. Am. Chem. Soc. 65(1943) pp. 267-8.

TOBIAS E. LEVOW, Primary Examiner A. P. DEMERS, Assistant Examiner US.Cl. X.R.

252-431 R; 260-63 K, 66, 86.3, 88.3 R, 89.3, 93.5 R, 94.2 R

